QUÉBEC CITY, June 4, 2012 /CNW Telbec/ - Aeterna Zentaris Inc. (NASDAQ:
AEZS) (TSX: AEZ) (the "Company") today announced that Johanna Bendell,
MD, Director of Gastrointestinal Cancer Research and Associate Director
of Drug Development at the Sarah Cannon Research Institute in
Nashville, Tennessee, presented Phase 3 results for perifosine in
refractory colorectal cancer yesterday, at the American Society of
Clinical Oncology (ASCO) Annual Meeting which is being held in Chicago.
Dr. Bendell was the lead investigator of the trial. Data showed no
benefit in overall survival when adding perifosine to capecitabine in
the refractory colorectal cancer setting, confirming top line results
previously disclosed by the Company on April 2, 2012.

For the total intent to treat (ITT) patient population, median OS was
6.9 months for the CAP group compared to 6.4 months for the P-CAP
group. Median PFS was 11.4 months for the CAP group compared to 10.9
months for the P-CAP group. The differences were not statistically
significant. There were 7 complete and partial responses in the CAP
group compared to 6 complete and partial responses in the P-CAP group.

In one pre-defined subgroup to which patients were stratified, those who
expressed the wild-type K-ras proto-oncogene and who had discontinued
oxaliplatin for toxicity rather than for disease progression, there was
a benefit in OS (P-CAP = 8 versus CAP = 6.2 months) and in PFS (P-CAP =
18.6 versus CAP = 6.6 months) for perifosine treated patients. The
reason for this finding is not clear at present and further analysis,
including biomarkers studies, are ongoing.

Juergen Engel, PhD, President and CEO at Aeterna Zentaris commented,
"These data confirm the disappointing topline results disclosed in
April. However, they do not deter us from our decision to continue the
Phase 3 trial in multiple myeloma which, as previously stated, was
based first and foremost on existing solid preclinical and clinical
data, and on the support for this drug among key opinion leaders in
this field. Additionally, we believe that market opportunity, examples
of other drugs enjoying success after facing setbacks, as well as the
reasonable investment required to move forward with this study up to
the predefined interim analysis, also make this a sound decision for
the Company. Perifosine in multiple myeloma remains a key component of
our deep pipeline focused on providing novel, targeted treatment
options for cancer patients facing unmet medical needs."

Perifosine is a novel, oral anticancer compound that inhibits Akt
activation in the phosphoinositide 3-kinase (PI3K) pathway. It works by
interfering with membranes of cancer cells, thereby inhibiting Akt
signaling which then affects cell death, growth, differentiation and
survival. Perifosine is currently in a Phase 3 trial in multiple
myeloma. In this indication, it has been granted orphan drug and Fast
Track designations by the FDA, as well as positive Scientific Advice
and orphan medicinal product designation from the EMA. Rights for
perifosine have been out licensed to Yakult Honsha for Japan, to Handok
for Korea and to Hikma Pharmaceuticals for the Middle East and certain
countries in North Africa. Aeterna Zentaris holds rights for the rest
of the world.

About Aeterna Zentaris

Aeterna Zentaris is an oncology and endocrinology drug development
company currently investigating treatments for various unmet medical
needs. The Company's pipeline encompasses compounds at all stages of
development, from drug discovery through to marketed products. For more
information please visit www.aezsinc.com.

Forward-Looking Statements

This press release contains forward-looking statements made pursuant to
the safe harbour provisions of the U.S. Securities Litigation Reform
Act of 1995. Forward-looking statements involve known and unknown risks
and uncertainties that could cause the Company's actual results to
differ materially from those in the forward-looking statements. Such
risks and uncertainties include, among others, the availability of
funds and resources to pursue R&D projects, the successful and timely
completion of clinical studies, the risk that safety and efficacy data
from any of our Phase 3 trials may not coincide with the data analyses
from previously reported Phase 1 and/or Phase 2 clinical trials, the
ability of the Company to take advantage of business opportunities in
the pharmaceutical industry, uncertainties related to the regulatory
process and general changes in economic conditions. Investors should
consult the Company's quarterly and annual filings with the Canadian
and U.S. securities commissions for additional information on risks and
uncertainties relating to forward-looking statements. Investors are
cautioned not to rely on these forward-looking statements. The Company
does not undertake to update these forward-looking statements. We
disclaim any obligation to update any such factors or to publicly
announce the result of any revisions to any of the forward-looking
statements contained herein to reflect future results, events or
developments, unless required to do so by a governmental authority or
by applicable law.